Speed control assembly

ABSTRACT

A mower including a handle assembly, a grip moveable relative to the handle assembly, a sensor operable to generate an output signal based on a position of the grip relative to the handle assembly, a drive assembly, and a controller coupled to the sensor and the drive assembly. The controller receives the output signal and controls the drive assembly according to the output signal.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a national phase filing under 35 U.S.C. 371 ofInternational Application No. PCT/US2018/038970 filed on Jun. 22, 2018,which claims priority to U.S. Provisional Patent Application No.62/524,179 filed on Jun. 23, 2017, the entire contents of which areincorporated herein by reference.

FIELD OF THE INVENTION

The present invention relates to a speed control system, and moreparticularly to a speed control system for a lawn mower.

SUMMARY OF THE INVENTION

The present invention provides, in one aspect, a mower including ahandle assembly, a grip moveable relative to the handle assembly, asensor operable to generate an output signal based on a position of thegrip relative to the handle assembly, a drive assembly, and a controllercoupled to the sensor and the drive assembly. The controller receivesthe output signal and controls the drive assembly according to theoutput signal.

The present invention provides, in another aspect, a mower including anupper arm, a cross member coupled to the upper arm, and a housingcoupled to the cross member and the upper arm. The mower furtherincludes a grip at least partially received within the housing. The gripis movable relative to the housing. A biasing member biasing the grip,and the biasing member is at least partially positioned within thehousing. A sensor is positioned within the housing, and the sensorgenerates a control signal based on the position of the grip withrespect to the housing. The mower further includes a controller thatreceives the control signal and operates the mower based on the controlsignal.

The present invention provides, in another aspect, a mower including adeck defining a handle pivot axis, a drive system, a handle membercoupled to the deck and rotatable with respect to the deck about thehandle pivot axis, a lower arm coupled to the handle member, a upper armtelescopically coupled to the lower arm, and a speed control assembly.The speed control assembly includes a housing coupled to the upper armand a grip at least partially received within the housing and movablerelative to the upper arm. The speed control assembly further includes asensor positioned within the housing. The sensor detecting displacementof the grip relative to the upper arm and generating a control signal. Acontroller receives the control signal and operates the drive systembased on the control signal.

Other features and aspects of the invention will become apparent byconsideration of the following detailed description and accompanyingdrawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of a lawn mower including a speed controlassembly in accordance with an embodiment of the invention.

FIG. 2 is a partial section view of the lawn mower of FIG. 1 taken alongthe line 2-2 shown in FIG. 1 .

FIG. 3 is a front view of the lawn mower and the speed control assemblyof FIG. 1 .

FIG. 4A is a section view of the speed control assembly taken along theline of 4A-4A shown in FIG. 3 , illustrating a grip of the speed controlassembly in a first position.

FIG. 4B is another section view of the speed control assembly and takenalong the line of 4A-4A shown in FIG. 3 , illustrating the grip of thespeed control assembly in a second position.

FIG. 5 is a perspective view of a speed control assembly in accordancewith another embodiment of the invention.

FIG. 6 is a perspective view of a speed control assembly in accordancewith another embodiment of the invention.

FIG. 7 is a front view of a speed control assembly in accordance withanother embodiment of the invention.

Before any embodiments of the invention are explained in detail, it isto be understood that the invention is not limited in its application tothe details of construction and the arrangement of components set forthin the following description or illustrated in the following drawings.The invention is capable of other embodiments and of being practiced orof being carried out in various ways. Also, it is to be understood thatthe phraseology and terminology used herein is for the purpose ofdescription and should not be regarded as limiting.

DETAILED DESCRIPTION

FIGS. 1 and 2 illustrate a lawn mower 10 including a handle assembly 14pivotally coupled to a main body 18 that supports a drive systemassembly 22 (FIG. 2 ). The drive system 22 includes, for example, anelectric motor 24 powered by a battery pack 80 received within the mainbody 18. The motor 24 drives a set of wheels 26, which support the mainbody 18 for movement over a surface. In the illustrated embodiment, therear wheels 26 are driven by the drive system 22, but alternativeembodiments include both the front and the rear wheels being driven bythe drive system 22. A transmission is coupled to the motor 24 to reducethe rotational speed from the motor 24 and to transfer the motor torqueto the wheels 26. The mower 10 further includes a cutting element 28rotationally supported on a mower deck 20 positioned beneath the mainbody 18. The cutting element 28 is ultimately driven by the motor 24. Inalternative embodiments, the cutting element 28 may be driven by a motorseparate from the motor that drives the wheels 26. As described ingreater detail below, the mower 10 also includes a speed controlassembly 30 that controls the operation of the drive system 22. Morespecifically, the speed control assembly 30 automatically controls theground travel speed of the lawn mower 10 based on a user's walking pace.

With continued reference to FIGS. 1 and 2 , the handle assembly 14 ispivotally coupled to the main body 18 such that the handle assembly 14may be rotated between discrete positions relative to the main body 18.The handle assembly 14 includes a pair of lower arms 35 and a pair ofupper arms 32. The pair of upper arms 32 include a first upper arm 33operable to translate along a first longitudinal axis 433 and a secondupper arm 34 operable to translate along a second longitudinal axis 434.In the illustrated embodiment, the first longitudinal axis 433 isparallel to the second longitudinal axis 434. The handle assembly 14further includes a cross member 62 that extends transversely between thefirst upper arm 33 and the second upper arm 34 to, among other things,provide lateral support for the handle assembly 14. In the illustratedembodiment, the cross member 62 is integral with the upper arms 32 at anupper end 33 a of the first upper arm 33 and integral with an upper end34 a of the second upper arm 34. In particular, a first corner 63 isformed at the connection of the first upper arm 33 and the cross member62, and a second corner 64 is formed at the connection of the secondupper arm 34 and the cross member 62. In other embodiments, the crossmember 62 is removably coupled to the pair of upper arms 32. The pair ofupper arms 32 are telescopically received by the pair of lower arms 35through a first adjustment connector 44 and a second adjustmentconnector 45. In other words, the distance the upper arms 32 extend awayfrom lower arms 35 is adjustable by a user via the connectors 44, 45.

The pair of lower arms 35 includes a first lower arm 36 and a secondlower arm 37. The first lower arm 36 is coupled to a first offset armhandle member 39, and the second lower arm 37 is coupled to a secondoffset arm handle member 40. The first offset arm 39 is pivotallycoupled to a first bracket 41 of the mower deck 20 about a first handlepivot axis 441. Likewise, the second offset arm 40 is pivotally coupledto a second bracket 42 of the mower deck 20 about a second handle pivotaxis 442. The handle assembly 14 also includes a locking mechanism 38coupled to the pair of lower arms 35 to releasably retain the handleassembly 14 at various pivoted positions relative to the main body 18.In other words, the locking mechanism 38 is operable to secure thehandle assembly 14 in various positions (e.g., a storage position, avertical position, a small-angle position, a large-angle position, etc.)relative to the main body 18.

With reference to FIG. 3 , the speed control assembly 30 includes aU-shaped grip 46 with a gripping portion 50 and a pair of grip legs 54,including a first grip leg 55 and a second grip leg 56. The grippingportion 50 is oriented substantially parallel to the cross member 62,and the gripping portion 50 extends the entire width of the cross member62. The first grip leg 55 is slidably coupled to the first upper arm 33,and the second grip leg 56 is slidably coupled to the second upper arm34. As such, the grip 46 is moveable relative to the handle assembly 14.A bail control 57 is also positioned on the grip 46.

With continued reference to FIGS. 2-3 , the speed control assembly 30further includes a first housing 60 and a second housing 61. Both thefirst housing 60 and the second housing 61 are formed as clam-shellhousings that partially enclose the grip 46 and the handle assembly 14,and both housings 60, 61 are coupled to the cross member 62. Inparticular, the first grip leg 55 is partially received by the firsthousing 60, and the second grip leg 56 is partially received by thesecond housing 61. The first housing 60 is coupled to the first corner63 of the handle assembly 14 and the second housing 61 is coupled to thesecond corner 64 of the handle assembly 14. In other words, the U-shapedgrip 46 is partially received within both the first housing 60 and thesecond housing 61.

With reference to FIG. 4A, the legs 54 of the grip 46 are telescopicallycoupled to the upper arms 32. Specifically, the first grip leg 55 isreceived within a hollow portion 58 of the first housing 60, such thatthe grip 46 is linearly displaceable (e.g., slidable) along the firstlongitudinal axis 433 relative to the first upper arm 33. In a similarmanner, the second grip leg 56 is received within a hollow portion ofthe second housing 61 such that the grip 46 is linearly displaceablealong the second longitudinal axis 434 relative to the second upper arm34. In particular, a rod 59 extends from the first grip 46 to the firstupper arm 33. In alternate embodiments, the upper arms 32 are receivedwithin a hollow portion of the respective grip legs 54 (or vice versa)while the grip 46 remains linearly displaceable relative to the pair ofupper arms 32.

FIGS. 4A and 4B illustrate a section of the first housing 60, the grip46, and the cross member 62. The grip 46 is at least partially receivedwithin the first housing 60 and is coupled to the sensor 66. A biasingmember 84 is positioned within the first housing 60 and is biases thegrip 46 along the first longitudinal axis 433. Specifically, the biasingmember 84 is positioned between the grip 46 and the handle assembly 14.In the illustrated embodiment, the biasing member 84 is a linear springelement. In particular, the biasing member 84 acts upon the grip 46 andthe upper arms 32, to urge the grip 46 away from the cross member 62,toward an extended, first position (FIG. 4A). Similarly, the grip 46 ismovable toward the cross member 62, against the bias of the biasingmember 84 to a compressed, second position (FIG. 4B).

With reference to FIGS. 3, 4A and 4B, the speed control assembly 30further includes a sensing device (e.g., a sensor 66) positioned withinthe first housing 60. The sensor 66 is supported, for example, by thecross member 62 adjacent one of the legs 54 of the grip 46. The sensor66 detects and/or measures the displacement of the grip 46 relative tothe cross member 62 (and the upper arms 32). In the illustratedembodiment, the sensor 66 is an optical-encoder array. In alternativeembodiments, the sensing device 66 is a proximity sensor, a linearpotentiometer, a rotary potentiometer, a magnetic transducer, aHall-effect sensor, a photovalic sensor, a capacitive sensor, a digitalposition encoder, transducer, or other similar sensor. In furtheralternative embodiments, the sensor 66 may be an electrical switch thatis opened and closed in response to the grip 46 moving to apredetermined location relative to the cross member 62. Any suitablesensing device for measuring the displacement of the grip 46 relative tothe cross member 62 and the main body 18 is considered as part of thisinvention. For example, the sensing device may detect a force on thegrip 46 by a user, as described in greater detail with respect to FIG. 7.

With reference to FIG. 2 , the sensor 66 is electrically connected to acontroller 70 (e.g., a drive system controller, motor controller, etc.)with memory 74 and a processor 78. Specifically, the sensor 66 generatesan electrical output signal (i.e., a control signal) that is received bycontroller 70. The output signal from the sensor 66 is based on theposition of the speed control assembly 30. More specifically, the outputsignal is based on a position of the grip 46 relative to the handleassembly 14. The memory 74 of the controller 70 stores software settingforth operational parameters for the drive system 22 as determined bythe output signal received from the sensor 66. In particular, theprocessor 78 of the controller 70 executes the software to control thefunction of the drive system 22 (e.g., a speed and/or a direction atwhich the drive system 22 drives the wheels 26) based on the controloutput signal from the sensor 66. In other words, the controller 70receives the output signal from the sensor 66 and controls a speed ofthe drive system assembly 22 according to the output signal. In oneexample, the drive system controller 70 will measure a change in thecontrol signal over time as an input to alter the speed and/or directionat which the drive system 22 drives the wheels 26. The output signalfrom the sensor 66 varies with movement of the grip 46 relative to thecross member 62. In other words, the sensor 66 generates a controloutput signal (e.g., an analog signal or a digital signal) that isproportional to the magnitude of displacement of the grip 46 relative tothe cross member 62, or other suitable portion of the handle assembly14. Alternatively, when the sensing device is an electrical switch, acircuit containing the switch may be open or closed, either activatingor deactivating the motor 24.

The sensor 66 is positioned within the first housing 60, underneath thebiasing member 84. A first portion 66 a of the sensor 66 is fixed withrespect to the handle assembly 14, and a second portion 66 b of thesensor 66 is coupled to the first grip leg 55. In other words, thesecond portion 66 b is affixed within a recess 88 formed within thefirst grip leg 55 and is movable with the grip 46 as the grip 46translates along the first longitudinal axis 433. As such, the secondportion 66 b is movable relative to the first portion 66 a of the sensor66.

With reference to FIG. 4A, the grip 46 is in a first position. That is,the spring element 84 is uncompressed, and the sensing device 66 is notactuated. In the first position, the tab 66 b is at one end of thesensing device 66, and the mower 10 is controlled to have no groundspeed. With reference to FIG. 4B, the grip 46 is in the second position,which corresponds to maximum ground speed operation. That is, the springelement 84 is fully compressed and the sensing device 66 is fullyactuated. In the second position, the mower 10 is controlled to have amaximum ground speed, and the tab 66 b is at a full actuation distanceD1, indicating maximum compression of the spring element 84.

In operation, the grip 46 is moved between the extended, first position(FIG. 4A), in which the control signal does not actuate the drive system22 to drive the wheels 26, and the compressed, second position, in whichthe control signal actuates the drive system 22 to drive the wheels 26.The speed at which the wheels 26 are driven by the drive system 22 isdetermined by the compression of the grip 46 with respect to the handleassembly 14 (e.g., the cross member 62). In other words, the groundtravel speed of the lawn mower 10 is determined by the amount ofcompression that results from the user's pushing the grip 46 as the useris walking. More specifically, the grip 46 moves between the firstposition, in which the grip 46 is positioned at a first length L1measured from the gripping portion 50 to the cross member 62. In theillustrated embodiment, the first length L1 coincides with deactivationof the drive system 22 (i.e., zero ground travel speed). When the grip46 moves to a second position, the grip 46 is disposed at a secondlength L2 measured from the griping portion 50 to the cross member 62.The sensor 66 detects the displacement of the grip 46 and generates anoutput control signal that ultimately actuates the drive system 22 todrive the wheels 26 at a speed that matches the user's walking pace. Afull actuation distance D1 is defined as the difference in the firstlength L1 and the second length L2. Between the first position and thesecond position, the drive system 22 may drive the wheels 26 at avariable speed that is proportional to the percentage of the actuationdistance D1 that the grip 46 has been displaced. For example, if thegrip 46 is moved halfway between the first position and the secondposition, the drive system 22 drives the wheels 26 at half of thepredetermined speed.

In response to the grip 46 moving with respect to handle assembly 14,the output electrical signal is generated by the tab 66 b moving withrespect to the first portion 66 a of the sensor 66. In other words, thesensor 66 measures the displacement of the grip 46 against the springelement 84 in order to gauge the user's desired speed. The output signalfrom the sensor 66 is received and processed by the drive systemcontroller 70 and the controller 70 drives the motor 24 to drive thewheels 26 at a corresponding speed. An increase of force exerted on thegrip 46 by the user results in the grip 46 further compressing thespring 84 and further moving the tab 66 b with respect to the firstportion 66 a. Such an increase in translation would alter the outputsignal from the sensor 66 to request an increase of power to theelectric motor 24 and a greater speed of the mower 10.

With reference to FIG. 5 , a speed control assembly 130 in accordancewith another embodiment of the invention is coupled to a correspondinghandle assembly 114. The speed control assembly 130 and the handleassembly 114 are similar to the speed control assembly 30 and handleassembly 14 shown in FIGS. 1-3 , and common elements will have the samereference numeral plus “100”. As shown in FIG. 5 , the speed controlassembly 130 further includes a support member 182, which extendsbetween the grip 146 and the cross member 162, and which is movable withthe grip 146 relative to the cross member 162. In this embodiment, thesensing device 166A may be supported centrally on the cross member 162for actuation by the support member 182. In this configuration, thesensing device 166A may be a “plunger style” sensor that is actuatedwhen the support member 182 is displaced relative to the cross member162 (i.e., when the grip 146 is displaced upon actuation) along thefirst longitudinal axis 433 and the second longitudinal axis 434.Alternatively, as described above and shown in FIG. 3 , the sensingdevice 166B may be a “slide style” sensor that is supported at one ofthe ends of the cross member 162 and that is actuated by relativemovement between the grip 146 and the cross member 162 connected to thearms 132.

FIG. 6 illustrates a speed control assembly 230 in accordance with yetanother embodiment of the invention coupled a corresponding handleassembly 214. The speed control assembly 230 and the handle assembly 214are similar to the speed control assemblies 30, 130 and handleassemblies 14, 114 shown in FIGS. 1-3 or FIG. 5 , and common elementswill have the same reference numeral as the embodiment shown in FIGS.1-3 plus “200”. The speed control assembly 230 includes a grip 246pivotally coupled to the cross member 262 and/or the arms 234 of thehandle assembly 214. The sensing device 266 is actuated by pivoting thegrip 246 from the first position (shown with line shading) to the secondposition (shown without line shading) in a clockwise direction about thefirst grip pivot axis 455 and the second grip pivot axis 456 from theframe of reference of FIG. 6 . In other words, the sensing device 266detects the amount of pivotal rotation of the grip 246. Similar to thespeed control assembly 30 described above, the grip 246 is biasedtowards the first position by a biasing member (e.g., a torsion spring).In further alternative embodiments, the sensing device 266 is a torquesensor to measure the amount of torque a user places on the grip 246.

FIG. 7 illustrates a speed control assembly 330 in accordance with afurther embodiment of the invention coupled to a corresponding handleassembly 314. The speed control assembly 330 and the handle assembly 314are similar to the speed control assemblies 30, 130, 230 and handleassemblies 14, 114, 214 shown in FIGS. 1-3 , FIG. 5 or FIG. 6 , andcommon elements will have the same reference numeral as the embodimentshown in FIGS. 1-3 plus “300”. The speed control assembly 330 includes agrip 346 coupled to the pair of upper arms 332 of the handle assembly314. In this embodiment, the grip 346 is only marginally movablerelative to the upper arms 332 of the handle assembly 314. The sensingdevice 366 is a pressure or force-sensitive device (i.e., a forcesensor) that detects a force F applied to the grip 346 by a user in thedirection of the handle assembly 314 (e.g., down in FIG. 7 ).

Although the invention has been described in detail with reference tocertain preferred embodiments, variations and modifications exist withinthe scope and spirit of one or more independent aspects of the inventionas described.

What is claimed is:
 1. A mower comprising: a handle assembly including across member; a grip moveable longitudinally relative to the crossmember; a sensor operable to generate an output signal based on aposition of the grip relative to the cross member; a drive assembly; anda controller coupled to the sensor and the drive assembly; wherein thecontroller receives the output signal and controls the drive assemblyaccording to the output signal.
 2. The mower of claim 1, furthercomprising a housing coupled to the handle assembly, wherein the grip isat least partially received within the housing.
 3. The mower of claim 2,wherein the sensor is positioned within the housing.
 4. The mower ofclaim 1, wherein the output signal is proportional to the magnitude ofdisplacement of the grip relative to the cross member.
 5. The mower ofclaim 2, wherein the housing is coupled to a corner of the handleassembly.
 6. The mower of claim 1, wherein the sensor is a transducer.7. The mower of claim 1, further comprising a wheel coupled to the driveassembly, and wherein the controller controls a speed of the wheelaccording to the output signal.
 8. The mower of claim 1, wherein thedrive assembly includes an electric motor.
 9. The mower of claim 1,wherein a first portion of the sensor is coupled to the grip and moveswith the grip as the grip moves relative to the handle assembly; andwherein a second portion of the sensor is fixed with respect to thehandle assembly.
 10. The mower of claim 1, wherein the grip translatesalong a longitudinal axis of the handle assembly.
 11. The mower of claim1, further comprising a biasing member positioned between the grip andthe handle assembly.
 12. The mower of claim 1, further comprising acutting element rotationally supported on a mower deck.
 13. A mowercomprising: a first upper arm; a second upper arm; a cross memberextending transversely between the first upper arm and the second upperarm; a first housing coupled to the cross member and the first upperarm; a second housing coupled to the cross member and the second upperarm; a grip at least partially received within the first housing and thesecond housing, wherein the grip is movable relative to the first andsecond housings; a biasing member biasing the grip, the biasing memberat least partially positioned within the housing; a sensor positionedwithin the housing, wherein the sensor generates a control signal basedon the position of the grip with respect to the cross member; and acontroller that receives the control signal and operates the mower basedon the control signal.
 14. The mower of claim 13, wherein the sensor isan optical-encoder array.
 15. The mower of claim 13, wherein the sensoris a force sensor operable to measure the amount of force applied to thegrip by a user.
 16. The mower of claim 13, further comprising a lowerarm pivotally coupled to a bracket attached to a deck of the mower andwherein a lower end of the upper arm is telescopically received by anupper end of the lower arm.
 17. The mower of claim 13, wherein the griptranslates along a longitudinal axis defined by the upper arm.
 18. Themower of claim 13, wherein the grip is pivotally coupled to the upperarm.
 19. A mower comprising: a deck defining a handle pivot axis; adrive system; a handle member coupled to the deck and rotatable withrespect to the deck about the handle pivot axis; a lower arm coupled tothe handle member; an upper arm telescopically coupled to the lower arm;and a speed control assembly including: a housing coupled to the upperarm; a grip at least partially received within the housing and movablerelative to the upper arm; a sensor positioned within the housing, thesensor detecting displacement of the grip relative to the upper arm andgenerating a control signal, and a controller that receives the controlsignal and operates the drive system based on the control signal,wherein the control signal is proportional to the magnitude ofdisplacement of the grip relative to the upper arm.
 20. The mower ofclaim 19, wherein the upper arm defines a longitudinal axis and the griptranslates along the longitudinal axis.